Do we know for sure that she has not gardened before? Or at least played at gardening?
I agree that it’s mostly for show—you can’t take care of a vegetable garden that really puts food on the table except by putting in at least several hours a day. You have to pay steady attention to things to get edible results in any quantity.
Those who say she’ll never get her hands dirty are going a bit too far. I’m quite sure she will, but largely for show. Someone else will actually have to be in charge of this garden. But I think we overreach if we assume that she won’t actually be involved at all.
And most of the people in the demographic the Axelrod cabal are aiming at won’t know difference between what’s for show and what’s not.